Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Platelet-aggregating factor (PAF) was removed from bovine plasma by human platelets fixed with 2% formaldehyde. The degree of adsorption was directly related to the platelet concentration and the length of incubation. Fixed washed platelets (FWP) aggregated with bovine plasma could be deaggregated by 1M KCl, Evans blue, and 8M urea but not by beta-galactosidase. Incubation with 1M KCl eluted some but not all of the PAF, as the deaggregated platelets spontaneously aggregated upon removal of the deaggregating conditions. Also, fixed platelets adsorbed PAF even in the presence of 1M salt or after treatment with Evans blue. Platelet aggregation was not affected by thrombin (20 micron/ml) but was abolished by trypsin at concentrations as low as 4 X 10(-1) microgram/ml. The data suggest that deaggregation is not the result of elution of the loosely bound aggregating factor from the platelet surface, but rather the disruption of noncovalent interplatelet bridging between one or more PAF molecules bound to a specific receptor.
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PMID:Platelet-aggregating factor and the aggregation of fixed washed platelets. 1 45

With slight modification of a trypsin digestion technique, Rickettsia rickettsii were demonstrated specifically by immunofluorescence staining in Formalin-fixed, paraffin-embedded tissue sections from a human, rhesus monkey, and guinea pig with Rocky Mountain spotted fever and in infected membranes from a chicken embryo. Tissues were cut at 4 micron and, using geltain as a tissue adhesive, were hydrated in a routine manner. Sections were then digested in refrigerated 0.1% trypsin for 16 h, washed, and stained specifically for R. rickettsii by direct or indirect immunofluorescence. Rickettsial organisms were localized in affected vessels of the mammalian species and within the yolk sac epithelium of the chicken embryo. Specificity was confirmed by adsorbing antibody conjugates with R. rickettsii organisms. Trypsin digestion probably decreased tissue proteins which interfered with immunochemical attachment of antibody to the rickettsiae. The technique is valuable in that a diagnosis of Rocky Mountain spotted fever can be confirmed from Formalin-fixed tissues processed in a routine manner.
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PMID:Identification of Rickettsia rickettsii in formalin-fixed, paraffin-embedded tissues by immunofluorescence. 10 May 9

Immunohistochemical studies of paraffin sections of formaldehyde-fixed material and formaldehyde-fixed cryostat sections treated with trypsin or other enzymes were undertaken. Formaldehyde treatment resulted mostly in partial or total loss of antigenicity, as visualized by fluorescent antibody technique in tissue sections. The digestion of sections with trypsin resulted usually in total or partial restitution of antigenicity, previously altered with formaldehyde. This effect is suggested to consist primarily in breaking formaldehyde-induced intermolecular cross-links. Restitution of antigenicity altered by formaldehyde can also be achieved on using pepsin or other proteolytic enzymes, or by some other technique. When the effect of one enzyme proves insufficient, it can readily be complemented by the action of another enzyme applied subsequently. Mild trypsin treatment preserves well the morphological structure of most tissues.
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PMID:Immunohistochemical analysis of formaldehyde- and trypsin- or pepsin-treated material. 10 8

The ponderal quantity of 140 S antigens and their peptide distribution are controlled in concentrated virulent and inactivated preparations proir to their being transformed into vaccines. A certain variability in the amount of 140 S particles and in the titer of peptide sensitive to trypsin (VP1) has been demonstrated in the virulent preparations. After treatment by inactivating agents (glycidaldehyde, binary ethyleneimine and formaldehyde) two types of alteration of the viral capsid are shown : one leads to the partial cleavage of VP1 (glycidaldehyde and binary ethyleneimine), the other leads to the detaching of an important quantity of VP1 from the capsid (formaldehyde). The degradation by formadehyde of the 140 S particles of type O and type C into 12 S particles is underlined, as well as the relatuve stability of type A and the relatuve lability of type C. The results are discussed in terms of immunogenicity.
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PMID:[Routine physico-chemical testing of concentrated virulent and inactivated foot-and-mouth disease virus antigens]. 19

Chemical modifications of human plasma alpha1-antitrypsin with reagents which modify lysyl residues (citraconic anhydride, acetic anhydride, formaldehyde and 2,4,6-trinitrobenzenesulfonic acid) and arginyl residued (1,2-cyclohexanedione) were examined with regard to their effect upon the elastase inhibitory capacity of the glycoprotein. 2,4,6-Trinitrobenzenesulfonic acid was employed to quantitate the remaining free amino groups (epsilon-NH2 groups of lysine) and the extent of modifications. Amino acid analysis was utilized in the same capacity for the guanidino groups of arginyl residues. The elastase inhibitory capacity of alpha1-antitrypsin was destroyed following trinitrophenylation, citraconylation and acetylation. Circular dichroism of the native and modified derivatives revealed major changes in conformation following trinitrophenylation and citraconylation while CD profiles of acetylated and reductively methylated derivatives differed from that of the native profile considerably less. Reductively methylated alpha1-antitrypsin retained its elastatse inhibitory capacity. The reaction of 1,2-cyclohexanedione with alpha1-antitrypsin did not effect in a loss in inhibitory capacity. Gel filtration studies of native and modified alpha1-antitrypsin on Sephadex G-100 demonstrated an increased molecular weight presumably through molecular aggregation, in the citraconylated and trinitrophenylated derivatives, but not in the cases of the other derivatives. Based upon these studies and previous investigations of our laboratory, it was concluded that (1) alpha1-antitrypsin is a lysyl inhibitor type (i.e., the reactive site is a Lys-X bond), (2) its interaction with elastase follows a pattern similar to trypsin and chymotrypsin, and (3) the positively charged epsilon-NH2 group of lysine is essential for the maintenance of elastase inhibitory capacity.
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PMID:Circular dichroism of chemically modified human plasma alpha1-antitrypsin. Interaction with porcine elastase. 31 Mar 16

The receptors for aggregated immunoglobulin G (IgG) (an Fc receptor) and for ristocetin-von Willebrand factor on human platelets were studied by means of various modifications of the platelet surface. The expression of these receptors was measured by the agglutination of platelets to ristocetin in the presence of von Willebrand factor, which is part of the factor VIII complex, and by the binding of aggregated IgG coupled to 3H-labelled diazobenzene. Treatment of platelets with chymotrypsin, trypsin, papain and pronase which removed protein and glycoprotein from the platelet under conditions where the release reaction was inhibited caused loss of the expression of the receptor for ristocetin-von Willebrand factor and an enhancement of that for aggregated IgG. Induction of membrane changes with ADP and of the release reaction with the ionophore A23187 abolished agglutination to ristocentin-von Willebrand factor but did not alter the receptor for aggregated IgC. Possible contributions of unspecific membrane changes, produced by protease treatment of platelets, to the modification of receptor expression were eliminated by the use of formaldehyde-treated platelets. Trypsin, papain and pronase destroyed the ability of these platelets to agglutinate to ristocetin-von Willebrand factor but produced no change in the binding of aggregated IgC. Therefore, the receptor for ristocetin-von Willebrand factor is truly sensitive to proteolysis while the Fc receptor is not, but is partially masked by protease-sensitive material.
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PMID:A comparative study of the effect of modification of the surface of human platelets on the receptors for aggregated immunoglobulins and for ristocentin-von Willebrand factor. 31 30

Casein epsilon-aminolysyl residues were converted to the methyl (and dimethyl), isopropyl or cyclopentyl derivatives in high yield with formaldehyde, acetone or cyclopentanone, respectively, in the presence of sodium borohydride. When incorporated into diets at 10% as the sole protein source, the chemically modified caseins failed to support growth of young rats. Methyl casein did, however, support limited growth after about 5 days. Plasma threonine levels increased and lysine levels decreased markedly in rats fed the alkyl caseins. The respective alkyllsine derivatives were present in plasma and urine. In another experiment, nearly normal or normal growth was obtained by feeding lysine-supplemented methyl or isopropyl casein, respectively. A preparation of partially methylated casein, containing approximately equal amounts of monomethyl- and dimethyllysines, supported normal rat growth. These results demonstrate that lysine deficiency was produced by feeding highly alkylated caseins. Digestibility of the chemically modified caseins in vivo was not affected, although in vitro studies with trypsin and alpha-chymotrypsin showed lowered digestibility. Since no apparent toxicity was observed limited methylation of food proteins may be useful for protection of lysyl residues against deteriorative reactions during processing and storage.
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PMID:Effect of reductive alkylation of the epsilon-amino group of lysyl redsidues of casein on its nutritive value in rats. 56 44

Treatment of chromatin subunits (nucleosome monomers) with formaldehyde results in the formation of cross-links between DNA and histones and between histones and histones. Digestion of chromosomal proteins with proteinase K does not lower the protein/DNA weight ratio below 0.08 to 0.1 as determined by cesium chloride gradient centrifugation of the digestion product from formaldehyde-treated nucleosomes. In addition to proteinase K, formaldehyde-treated nucleosomes were tested for accessibility to trypsin and pronase. The CsCl gradient patterns show, that pronase digestion and proteinase K treatment yield similar results. Trypsin treatment of control and formaldehyde-treated nucleosomes shows, that the sites which are accessible for trypsin in native nucleosomes, are blocked after formaldehyde treatment. Analysis of the CsCl gradient peak fractions in polyacrylamide gels shows, that the reliability of DNA fragment size determinations depends on the completeness of deproteinization.
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PMID:Digestion of chromosomal proteins in formaldehyde treated chromatin. 56 16

In the present study we investigated the antiinflammatory effect of pentosanpolysulfate (SP 54) in combination with metamizol using different forms of rat paw edema (induced by dextrane, hyaluronidase, trypsin, formaldehyde, carragenine or kaolin). After s. c. application Probaphen, a new drug containing pentosanpolysulfate, metamizol, and lidocaine, proved in our experiments to exert an antiphlogistic effect about 40% stronger than the equivalent amount of SP 54 alone. Since pentosanpolysulfate by itself has no analgetic activity, its combination with metamizol results in a formulation which is not only a more potent antiinflammatory drug but will aslo counteract pains which accompany most edematous reactions. Probaphen may therefore be suggested for the treatment of rheumatoid arthritis and similar inflammatory and edematous processes. First clinical studies and reports on Probaphen fully support our pharmacological results.
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PMID:[Pharmacological studies on the antiphlogistic effect of pentosanpolysulfate in combination with metamizol]. 57 70

Low concentrations of protease and trypsin reduced the electrophoretic mobility (EPM) of thymocytes; with higher concentrations it was normal or above. Differences in membrane structure of thymocytes, T and B cells was found as B cells showed no reduction while T cells gave intermediate values. Further the reduction was greater with protease than with trypsin. Formalin fixation increased the EPM of all normal cell types to a similar degree. The EPM of proteolytically treated thymocytes and B cells was increased to a similar level and to a greater degree than neuraminidase-treated thymocytes. Small amounts of sialic acid were detected in the supernatant after proteolytic treatment of thymocytes. Protease reduced the binding of anti-lymphocyte serum, while no definite effect was obtained with trypsin. Neither sublytic doses of phospholipase C nor ribonuclease appeared to change the EPM.
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PMID:Electrophoresis of lymphoid cells. Differences in the cell membrane structure of murine thymocytes, T and B cells revealed by enzyme and formalin treatment. 76 20


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